;; Standard Library Procedures and Macros ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;; MISC
+;; MISC ESSENTIAL PROCEDURES
+
+(define list
+ (lambda args args))
+
+(define map
+ (lambda (proc l)
+ (if (null? l)
+ '()
+ (cons (proc (car l)) (map proc (cdr l))))))
+
+(define join-lists
+ (lambda (l1 l2)
+ (if (null? l1)
+ l2
+ (cons (car l1) (join-lists (cdr l1) l2)))))
+
+; Append an arbitrary number of lists together
+(define append
+ (lambda lists
+ (if (null? lists)
+ ()
+ (if (null? (cdr lists))
+ (car lists)
+ (join-lists (car lists) (apply append (cdr lists)))))))
+
+
+;; DERIVED FORMS
+
+;; define
+
+(define-macro (define args . body)
+ (if (pair? args)
+ (list 'define (car args) (join-lists (list 'lambda (cdr args)) body))
+ 'no-match))
+
+;; not
+
+(define-macro (not x)
+ (list 'if x #f #t))
+
+;; let
+
+(define-macro (let args . body)
+ (join-lists
+ (list (join-lists (list 'lambda (map (lambda (x) (car x)) args)) body))
+ (map (lambda (x) (car (cdr x))) args)))
+
+;; quasiquote/unquote (one nesting level only)
+
+((lambda ()
+ (define (qqhelper l)
+ (if (null? l)
+ l
+ (let ((head (car l))
+ (tail (cdr l)))
+
+ (if (pair? head)
+ (if (eq? (car head) 'unquote)
+ (list 'cons (car (cdr head)) (qqhelper tail))
+ (if (eq? (car head) 'unquote-splicing)
+ (list 'join-lists (car (cdr head)) (qqhelper tail))
+ (list 'cons (list 'quasiquote head) (qqhelper tail))))
+ (if (symbol? head)
+ (list 'cons (list 'quote head) (qqhelper tail))
+ (list 'cons head (qqhelper tail)))))))
+
+ (define-macro (quasiquote arg)
+ (if (not (pair? arg))
+ (list 'quote arg)
+ (qqhelper arg)))))
+
+;; begin
+
+(define-macro (begin . sequence)
+ `((lambda () ,@sequence)))
+
+;; caddr etc.
+
+(define-macro (caar l) `(car (car ,l)))
+(define-macro (cadr l) `(car (cdr ,l)))
+(define-macro (cdar l) `(cdr (car ,l)))
+(define-macro (cddr l) `(cdr (cdr ,l)))
+(define-macro (caaar l) `(car (car (car ,l))))
+(define-macro (caadr l) `(car (car (cdr ,l))))
+(define-macro (cadar l) `(car (cdr (car ,l))))
+(define-macro (caddr l) `(car (cdr (cdr ,l))))
+(define-macro (cdaar l) `(cdr (car (car ,l))))
+(define-macro (cdadr l) `(cdr (car (cdr ,l))))
+(define-macro (cddar l) `(cdr (cdr (car ,l))))
+(define-macro (cdddr l) `(cdr (cdr (cdr ,l))))
+(define-macro (cadddr l) `(car (cdr (cdr (cdr ,l)))))
+
+;; let*
+
+(define-macro (let* args . body)
+ (if (null? args)
+ `(let () ,@body)
+ `(let (,(car args))
+ (let* ,(cdr args) ,@body))))
+
+;; while
+
+(define-macro (while condition . body)
+ (let ((loop (gensym)))
+ `(begin
+ (define (,loop)
+ (if ,condition
+ (begin ,@body (,loop))))
+ (,loop))))
-(define (not x) (if x #f #t))
+;; cond
+
+((lambda ()
+ (define (cond-predicate clause) (car clause))
+ (define (cond-actions clause) (cdr clause))
+ (define (cond-else-clause? clause)
+ (eq? (cond-predicate clause) 'else))
+
+ (define (expand-clauses clauses)
+ (if (null? clauses)
+ (none)
+ (let ((first (car clauses))
+ (rest (cdr clauses)))
+ (if (cond-else-clause? first)
+ (if (null? rest)
+ `(begin ,@(cond-actions first))
+ (error "else clause isn't last in cond expression."))
+ `(if ,(cond-predicate first)
+ (begin ,@(cond-actions first))
+ ,(expand-clauses rest))))))
+
+ (define-macro (cond . clauses)
+ (if (null? clauses)
+ (error "cond requires at least one clause.")
+ (expand-clauses clauses)))))
+
+;; and
+
+((lambda ()
+ (define (expand-and-expressions expressions)
+ (let ((first (car expressions))
+ (rest (cdr expressions)))
+ (if (null? rest)
+ first
+ `(if ,first
+ ,(expand-and-expressions rest)
+ #f))))
+
+ (define-macro (and . expressions)
+ (if (null? expressions)
+ #t
+ (expand-and-expressions expressions)))))
+
+;; or
+
+((lambda ()
+ (define (expand-or-expressions expressions)
+ (let ((first (car expressions))
+ (rest (cdr expressions)))
+ (if (null? rest)
+ first
+ `(if ,first
+ #t
+ ,(expand-or-expressions rest)))))
-(define (list . args) args)
+ (define-macro (or . expressions)
+ (if (null? expressions)
+ #f
+ (expand-or-expressions expressions)))))
-(define (caar l) (car (car l)))
-(define (cadr l) (car (cdr l)))
-(define (cdar l) (cdr (car l)))
-(define (cddr l) (cdr (cdr l)))
-(define (cadar l) (car (cdr (car l))))
+;; FUNCTIONAL PROGRAMMING
+
+(define (fold-left proc init l)
+ (if (null? l)
+ init
+ (fold-left proc (proc init (car l)) (cdr l))))
+
+(define (reduce-left proc init l)
+ (if (null? l)
+ init
+ (if (null? (cdr l))
+ (car l)
+ (fold-left proc (proc (car l) (car (cdr l))) (cdr (cdr l))))))
;; NUMBERS
(define (null? arg)
(eq? arg '()))
-(define (fold-left proc init l)
- (if (null? l)
- init
- (fold-left proc (proc init (car l)) (cdr l))))
-
-(define (reduce-left proc init l)
- (if (null? l)
- init
- (if (null? (cdr l))
- (car l)
- (fold-left proc (proc (car l) (car (cdr l))) (cdr (cdr l))))))
-
(define (+ . args)
(fold-left pair+ 0 args))
(define (integer? x) (= x (round x)))
(define (exact? x) (fixnum? x))
(define (inexact? x) (flonum? x))
+(define (number? x)
+ (if (fixnum? x) #t
+ (if (flonum? x) #t
+ (if (ratnum? x) #t #f))))
+
;; LISTS
(iter (cdr a) (fix:+ count 1))))
(iter l 0))
-; Join two lists together
-(define (join l1 l2)
- (if (null? l1)
- l2
- (cons (car l1) (join (cdr l1) l2))))
-
-; Append an arbitrary number of lists together
-(define (append . lists)
- (if (null? lists)
- ()
- (if (null? (cdr lists))
- (car lists)
- (join (car lists) (apply append (cdr lists))))))
-
; Reverse the contents of a list
(define (reverse l)
(if (null? l)
(append (reverse (cdr l)) (list (car l)))))
-;; LIBRARY SPECIAL FORMS
-
-; let
-
-(define (let-vars args)
- (if (null? args)
- '()
- (cons (caar args) (let-vars (cdr args)))))
-
-(define (let-inits args)
- (if (null? args)
- '()
- (cons (cadar args) (let-inits (cdr args)))))
-
-(define-macro (let args . body)
- `((lambda ,(let-vars args)
- ,@body) ,@(let-inits args)))
-
-; while
-
-(define-macro (while condition . body)
- (let ((loop (gensym)))
- `(begin
- (define (,loop)
- (if ,condition
- (begin ,@body (,loop))))
- (,loop))))
-
-; cond
-
-(define (cond-predicate clause) (car clause))
-(define (cond-actions clause) (cdr clause))
-(define (cond-else-clause? clause)
- (eq? (cond-predicate clause) 'else))
-
-(define (expand-clauses clauses)
- (if (null? clauses)
- (none)
- (let ((first (car clauses))
- (rest (cdr clauses)))
- (if (cond-else-clause? first)
- (if (null? rest)
- `(begin ,@(cond-actions first))
- (error "else clause isn't last in cond expression."))
- `(if ,(cond-predicate first)
- (begin ,@(cond-actions first))
- ,(expand-clauses rest))))))
-
-(define-macro (cond . clauses)
- (if (null? clauses)
- (error "cond requires at least one clause.")
- (expand-clauses clauses)))
-
-; and
-
-(define (expand-and-expressions expressions)
- (let ((first (car expressions))
- (rest (cdr expressions)))
- (if (null? rest)
- first
- `(if ,first
- ,(expand-and-expressions rest)
- #f))))
-
-(define-macro (and . expressions)
- (if (null? expressions)
- #t
- (expand-and-expressions expressions)))
-
-; or
-
-(define (expand-or-expressions expressions)
- (if (null? expressions)
- #f
- (let ((first (car expressions))
- (rest (cdr expressions))
- (val (gensym)))
- `(let ((,val ,first))
- (if ,val
- ,val
- ,(expand-or-expressions rest))))))
-
-(define-macro (or . expressions)
- (expand-or-expressions expressions))
-
-
;; TESTING
-(define-macro (backwards . body)
- (cons 'begin (reverse body)))
-
; Test for the while macro.
(define (count)
(define counter 10)
0
(fix:+ n (sum-recurse (fix:- n 1)))))
+
;; MISC
(define (license)
The Lambda Lab / projects / scheme.forth.jl.git / blobdiff